RU2533127C2 - Fluid medium valve, namely, back check valve for vanishing unit - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to the fluid medium valve and can be used in vanishing units, for example, for paint change, for pumping of residual paint, washing agent, foam, paint, air and/or compressed air from the paint pipeline, injection zone etc. to the return pipeline and/or stopping the paint free flowing downstream before running-off into the return pipeline. In the fluid medium valve the process of switchover of the fluid medium valve (8) is feedback controlled by the density of the matter at the inlet of the fluid medium. In the vanishing unit, in particular, for application of varnish on the structural members of the car body the back check valve (8) is a fluid medium valve according to any of items 1-26, and the main needle valve is a fluid medium valve according to any of items 1-26. The fluid medium valve (8) is used according to any of items 1-26 as a back check valve (8) in the vanishing unit for return of residual paint, washing agent, foam, paint, air and/or compressed air from the paint pipeline (5) for paint change. The valve (8) is also used as a main needle valve in the atomiser.

EFFECT: possibility of control of the back check valve for paint change with achievable smaller costs and higher accuracy.

28 cl, 28 dwg

Description

The invention relates to a valve for a fluid, in particular a check valve, which serves in a varnishing installation, for example, when changing paint, to direct residual paint, flushing agent, paint foam, air and / or compressed air from the paint line, discharge zone and etc. to the return line and / or to stop the current downstream paint on its own before draining into the return line.

On figa shows in a very simplified form, the usual varnish installation 1 for applying varnish on the structural elements of the car body, while the varnish installation 1 as the application device has a rotary spray 2 with a bell-shaped plate 3, which during operation gives out a spray stream 4 of varnish. In this case, the rotary sprayer 2 is supplied with the varnish to be applied through the paint line 5, while the main needle valve 6 is located in the paint line 5, which controls the flow of varnish to the rotary spray 2 and is open during the coating process. In addition, the known coating unit 1 has a return line 7, in which a return valve 8 is located, while the return line 7 leads to return, in order to collect and economically utilize residues arising from the change of paint (for example, flushing agent, paint residue, paint foam )

When changing the paint of the coating unit 1, the main needle valve 6 first closes, thereby interrupting the flow of varnish to the rotary spray 2. Then the check valve 8 opens and the paint pipe 5 is cleaned with flushing agent and pulsating air (shocks of compressed air), residues remaining in the paint line 5 for paint are directed through the open check valve 8 and through the return pipe 7 to return. Then, a new varnish of the desired color is supplied under pressure to the paint line 5 under pressure, while the main needle valve 6 is still closed, while the check valve 8 is open. The pressure supply can be completed when the paint foam or compressed air no longer comes out of the paint return line 7 downstream of the check valve 8, but only fresh paint. This is recognized in the coating system in this example by means of a photo relay, which consists of a light source 9 and an optical sensor 10, while the light source 9 and sensor 10 are located on opposite sides of the transparent return pipe 7 made in this example, so that the photo relay measures transparency for light exiting after the check valve 8 of the fluid. During the flushing of the paint line 5, a mixture of flushing means, residual paint and compressed air flows through the return line 7, and this mixture, due to the high proportion of air, is relatively permeable to light. However, after the paint is supplied under pressure to the paint line 5, a fresh varnish appears on the outlet of the check valve 8, which is almost free of compressed air and therefore relatively impervious to light. The sensor 10 is connected on the output side to a control unit 11, which closes the check valve 8 when the photo relay detects the appearance of fresh varnish at the output of the check valve 8.

FIG. 13B also shows a known modification of the coating system 1 according to FIG. 13A, with the difference that the return line 7 then branches downstream from the main needle valve 6 from the paint line 5.

The disadvantage of the known coating system 1, the description of which is given above, is that the return pipe 7 may become contaminated during operation, so that the photo relay can no longer measure the light permeability of the flowing fluid.

Another disadvantage of the above known coating system 1 is the reaction time between the activation of the optical sensor 10 and the closing of the check valve 8, while during the reaction time, fresh varnish is drawn out through the return pipe 7, which leads to corresponding paint losses.

In addition, in the above conventional coating unit 1, additional structural elements in the form of a light source 9 and an optical sensor 10 are required to control the check valve 8, thereby increasing the cost of manufacture and commissioning and increasing the sensitivity to interference.

In addition, it is also known from the prior art to control the check valve 8 when changing paint without a photo relay in accordance with a time program. In this case, it is assumed that when the paint is changed after the washing process at a certain point in time, a fresh varnish appears in the return pipe 7 downstream of the return valve 8.

A disadvantage of this known control of the check valve 8 by means of a time-dependent program is that the time required for changing the paint for flushing and subsequent supply of fresh varnish under pressure depends on the viscosity of the varnish, so that an incorrectly set viscosity or viscosity fluctuations lead to incorrect control of the return valve 8. If the check valve 8 closes too late, then fresh varnish is sent through the return pipe 7 to the return, which is associated with corresponding losses and paints. If the check valve 8 closes too early, then in the return pipe 5 there are still the remains of the previous washing process still upstream of the check valve 8, thereby negatively affecting the quality of varnish after opening the main needle valve 6.

Therefore, the basis of the invention is the corresponding improvement of the above conventional coating system 1, while, in particular, it should be possible to control the check valve 8 when changing colors with the lowest possible cost and possibly more accurately.

This problem is solved by using a check valve according to the invention, with the features of an independent claim.

The invention contains the general technical idea of using as a check valve for a fluid, which, depending on the fluid on the inlet side, switches with its own medium to the closed position and / or affects the transmission characteristics (for example, the flow characteristics of the fluid (preferably residual paint, flushing agent, air and / or compressed air) through the valve, while, for example, the transmission characteristics may preferably contain a leak fluid flow, fluid flow, fluid flow, opening position, closing position and / or one or more positions between the opening position and the closing position, which means that the valve position is not controlled externally by the valve actuator, but by the property (for example, viscosity) at the fluid inlet. In addition, this general technical idea can also be used, for example, to actuate a closing force amplifier using its own medium, depending on located on the inlet side of the fluid. Preferably, a valve can be provided that can direct the first fluid (e.g., residual paint, flushing agent, paint foam and air, e.g. compressed air) from the first pipe (e.g., paint pipe), respectively, from the first zone (e.g. , discharge zones) independently, respectively, using their own medium, into the second pipeline (for example, a return pipeline) and / or can prevent, independently or using their own medium, runoff into the second pipeline.

The fluid valve according to the invention has an opening position in which the fluid valve is at least partially open, in particular for flushing the paint line with flushing means and for injecting new paint into the pipe when the paint is changed.

In addition, the fluid valve according to the invention has a closing position in which the fluid valve is closed, in particular for applying a new varnish after a paint change.

The valve for the fluid allows for a permutation between the opening position and the closing position, while the permutation is carried out independently using the fluid located on the inlet side.

In the framework of the invention, at least a switching process occurs from the opening position to the closing position by means of its own medium due to the fluid located on the inlet side. However, it is also possible that the switching processes are carried out in both directions using their own environment. Thus, within the scope of the invention, there is also the possibility that the fluid valve is switched by its own medium from the closing position to the opening position.

In one preferred embodiment of the invention, the fluid valve is a check valve, as indicated at the beginning of the prior art, to direct the residual paint, flushing agent, paint foam and air, or compressed air, respectively, from the paint line to the return when changing ink. In a preferred embodiment of the invention, the check valve, due to its construction, distinguishes between the first medium (preferably a fluid) and the other, second medium (preferably another fluid), in particular, between a paint, on the one hand, and air, respectively, with compressed air containing air with foam and flushing agent, on the other hand, while the check valve switches, for example, independently and due to its design to the closing position, when the check valve has sides There is a certain environment at the entrance, in particular fresh paint. It is also possible that the valve, due to its design, distinguishes between a liquid (for example, flushing agent, (residual) paint, etc.), on the one hand, and a gaseous medium (for example, air, respectively compressed air), on the other hand. Conversely, the check valve according to the invention is preferably switched independently and due to its design to the opening position and / or remains at least in the opening position when there is air, respectively compressed air, or paint foam on the inlet side of the check valve. This independent control of the check valve, depending on the medium, makes it possible to refuse the external valve drive and costly sensors for distinguishing between fresh varnish, on the one hand, and flushing agent, residual paint and air, respectively compressed air, and paint foam, on the other hand. However, the invention is not limited to embodiments in which the control of the valve for the fluid is carried out exclusively independently depending on the medium. It is also possible within the scope of the invention that a fluid-independent valve control for a fluid is combined with an external control, as will be explained in more detail below.

In addition, the control according to the invention can preferably be used to achieve, respectively, activate the gain of the closing force. For example, a fluid valve, respectively a check valve, can be provided for independently and due to the design of activating the closing force amplifier (a detailed description of which will be given below) when there is paint on the inlet side of the fluid valve or the check valve. In addition, it is possible to provide a fluid valve, respectively a check valve, so that it independently and due to its design can carry out switching, control, in particular release of the locking mechanism, when on the inlet side of the valve for the fluid, respectively check valve, there is paint, due to which it can be achieved, respectively, the strengthening of the closing force is activated.

In a preferred embodiment of the invention, the valve for the fluid switches to the closing position on the basis of its independent depending on the control medium depending on the viscosity located on the inlet side of the fluid. So, a fresh varnish, which appears at the check valve during injection, has a higher viscosity than the air-containing foam of foam that occurs during washing. However, it is also within the scope of the invention that the fluid valve switches between the opening position and the closing position, depending on other properties of the fluid inlet side. For example, the process of switching a valve for a fluid can be controlled using mass density, state of aggregation, expansion under pressure, electrical conductivity, optical properties (e.g., permeability to light and color), thermal conductivity, vibrational characteristics, magnetic permeability, and / or pressure located on the inlet side of the fluid.

In a preferred embodiment of the invention, the fluid valve in the opening position is maximally open to allow flushing of the paint line with the maximum possible flow of flushing agent. In addition, the fluid valve may have, in addition to the opening position and the closing position, a standby position in which the fluid valve is at least partially open, for example, to wait for new paint when injecting new paint. The fluid valve according to the invention can be designed so that it independently and due to the action of its own medium switches to the closing position only from the standby position, but not from the opening position, while external valve control is required to switch from the opening position to fluid medium.

With this design of a fluid valve with three switching states (opening position, standby position and closing position), the fluid valve switches when the paint changes to the opening position, in order to allow the paint pipe to be flushed with the maximum possible flow of flushing agent. At the end of the flushing process, and thus at the beginning of the injection of new paint, the check valve is then switched from the open position to the standby position, and this switching process is preferably carried out by means of an external valve control. At the end of the injection process, a fresh varnish finally appears at the inlet of the check valve, due to which the check valve, due to its medium, switches from the standby position to the closed position.

As already mentioned briefly above, the invention is not limited to a fluid valve, which is controlled exclusively by its own medium. The invention also encompasses a fluid valve, which is further adapted for external control by means of a valve actuator, in particular with actuation of an external medium (for example, compressed air).

Therefore, the valve for the fluid according to the invention preferably has a first control inlet, and it is preferably the first connection for control air through which the control air can be supplied in order to switch to the closing position of the valve for the fluid actuated by an external Wednesday. In this case, the air supplied through the first connection for the control air, respectively compressed air, can serve to support the process of switching the valve for the fluid carried out by the own medium. However, it is also possible to switch the fluid valve to the closed position through the first control inlet regardless of the fluid on the inlet side.

In addition, the fluid valve according to the invention has, in one embodiment, a second control inlet through which the fluid valve can be switched to the opening position by actuation by the external medium. The second control inlet is also preferably a second control air connection through which air, respectively compressed air, can be supplied to control the fluid valve.

In one preferred embodiment of the invention, the fluid valve has a cylinder and a piston mounted in the cylinder so that the piston can move the locking body between the opening position and the closing position. In addition, the fluid valve in this embodiment has a valve seat, wherein the locking body closes the valve seat in the closing position, while in the opening position the locking body opens, respectively releases the valve seat. Thus, in this case, the movement of the valve is caused by the piston, which for this can be loaded on one side or on both sides by air, respectively, by compressed air. In addition, the piston can also be loaded on one side or on both sides by the spring force of the spring in order to set the desired neutral position.

In addition, in the framework of the present invention, the fluid valve may have a closing force amplifier that enhances the closing force generated by the own medium, for example, with the aim of possibly closing the valve for the fluid as quickly and as quickly as possible when on the side of the fresh ink the inlet of the check valve appears fresh paint.

The closing force amplifier can work, for example, with actuation by means of an external medium, in particular by means of air, respectively compressed air. However, as an alternative solution, it is also possible that the closing force amplifier works by means of a spring and / or tension mechanism, in particular, it creates an increased closing force by means of a spring and / or tension mechanism.

It is possible that the closing force amplifier comprises a locking mechanism, which can form, for example, a locking part (for example, an abutment plate, an abutment ring, etc.) located in the fluid valve fitting. The adjoining part preferably has a central opening and is provided, for example, for providing, at the circumferential edge, respectively near the central opening, a fitting section or a locking section. Part of the fit may preferably be mounted on the wall of the cylinder, respectively, the valve body for the fluid, respectively, the check valve.

In one embodiment, the locking mechanism is configured to switch, respectively, control, in particular blocking and / or unlocking. Particularly preferably, the locking mechanism (respectively, the locking) can be controlled, it can be switched accordingly, in particular, released using its own medium, depending on the fluid on the inlet side, in order to achieve, respectively, activate the amplification of the closing force and / or in order to achieve the closing position, respectively the translation of the valve for the fluid, respectively, the check valve, in the closing position.

Preferably, it is also possible that with the aid of a fluid (e.g. fresh paint, varnish, etc.) located at the valve (e.g., the valve closure body), the closing force amplifier is activated and / or the locking mechanism is released in order to achieve, respectively activation of reinforcement of the closing force, in particular by the fact that due to the release, the spring and / or tension mechanism (for example, a coil spring, respectively a compression spring) is released, due to which the locking body with reinforced force closing is pressed against the valve seat.

In one exemplary embodiment, the locking mechanism may be in the form of a snap, locking and / or clamping coupling mechanism.

With a pneumatic closing force amplifier, the closing force amplifier preferably has an amplification valve that selectively opens or closes the first connection for the control air that enters the cylinder and serves to close the valve for the fluid, wherein the closing force amplifier opens the amplification valve when actuated with By using the proprietary medium, controlling the valve for the fluid leads to a slight closing of the valve for the fluid, after which the amplification of the using the first connection for control air, and the closing force is enhanced.

In one exemplary embodiment of a closing force amplifier, the amplification valve is a check valve that has a valve gate that is connected to the piston so that movement of the piston results in a corresponding movement of the valve gate. In this case, the closing force amplifier is designed such that the valve shutter closes the first connection for the control air when the piston of the valve for the fluid is in the opening position. This means that there is no force support in the fluid opening position of the valve. In contrast, the closing force amplifier is configured such that the valve closure releases the first control air connection when the piston moves a fraction of its stroke from the opening position in the direction of the closing position so that power support then acts. Thus, when the closing movement of the valve for the fluid does not yet support the closing force in the opening position, but only when the piston has moved slightly from the opening position in the direction of the closing position.

In this case, there is an optional possibility that the first connection for the control air used to close the valve for the fluid radially or axially enters (i.e. equals to) the side surface of the cylinder.

When the first connection for control air is axially (axially) inserted into the cylinder, the first connection for control air is closed and, accordingly, opened by the piston directly or indirectly, while the inlet of the first connection for control air has a smaller cross section than the piston, and the ratio of the cross sections defines power gain. The strengthening of the closing force is based on the fact that the air pressure applied in the first connection for the control air with the inlet of the first connection closed for the control air acts only on a relatively small surface and therefore creates only a relatively small force. After opening the inlet of the first connection for control air, the air pressure applied in the first connection for control air acts on the entire piston surface, which is much larger than the inlet of the first connection for control air, so that the closing force acting on the piston increases.

Furthermore, within the scope of the invention, there is also the possibility that the closing force amplifier has a pressure-controlled pre-control valve, wherein the pre-control valve connects the first control air pipe to the first control valve air connection for the fluid, so that the pressure in the first pipe for the control air maintains a closing movement of the valve for the fluid when the pre-control valve is open. In this case, the control of the preliminary control valve is carried out depending on the fluid flowing in the inlet pipe of the valve. To this end, the pre-control valve preferably has a control inlet that is connected to a fluid valve inlet pipe, so that the pre-control valve opens when the pressure in the fluid valve inlet pipe rises at the end of the injection process.

In one embodiment of the invention, the fluid valve is in the form of a membrane valve and has an elastic membrane that carries a locking body. At the same time, the fluid closing valve body connected to the membrane can be mechanically connected to the piston, as already mentioned above. The piston allows external control of the fluid valve to the closing position and / or the opening position.

In addition, it is within the scope of the invention that the fluid valve has a locking body, preferably with a perforated disk, and holes in the form of slots can also be located in the perforated disk. The size of the holes in the perforated disk is chosen so that depending on the viscosity of the fluid on the inlet side, a certain closing force is created, which, when a certain viscosity limit is exceeded, closes the valve for the fluid.

As an alternative solution, the actuation of the fluid valve according to the invention by means of its own medium is realized in that in the opening position (respectively, in the standby position) there is only a small annular gap between the locking body and the surrounding valve seat. The width of the annular gap is chosen so that, depending on the viscosity of the flowing fluid, a pressure difference arises between the inlet side and the outlet side of the valve for the fluid, while the pressure difference acts on the locking body and creates a closing force.

If, for example, an air stream passes through a fluid valve, the fluid valve creates only a small flow resistance despite a narrow annular gap, so that the pressure difference between the inlet side and the outlet side of the fluid valve is small, resulting in a corresponding low closing force. Thus, in this case, the valve for the fluid remains in the open position, so that the air on the inlet side, respectively the compressed air, can pass almost unhindered.

If fresh varnish flows through the fluid valve, then the narrow annular gap of the fluid valve creates a higher flow resistance based on the higher viscosity of the varnish, resulting in a corresponding greater pressure difference between the inlet side and the outlet side of the fluid valve. The large pressure difference between the inlet side and the outlet side of the fluid valve in turn creates a closing force, whereby the fluid valve closes itself and / or the closing force is activated.

In addition, the fluid valve according to the invention may have a position sensor that detects what position the fluid valve is (for example, the opening position, the closing position and / or the standby position, respectively, the discharge position), in order to enable feedback, while the position sensor may be, for example, pneumatic, electrical or optoelectronic. It is also possible that the sensor detects only one specific position, in particular only the closing position.

In addition, it is within the scope of the invention that the locking body of the fluid valve is connected by means of a rod, respectively a mechanical compensating element, to the piston, while the compensating element allows a clearance between the locking body and the piston. In this case, the stroke of the compensating element is preferably greater than the movement of the locking body from the opening position to the closing position, so that the locking body without movement of the piston can be moved using its own medium from the opening position, respectively, from the standby position to the closing position.

In this embodiment, with a compensating element for connecting the piston to the locking body, an elastic membrane is preferably provided that moves the locking body in the gap zone to the open position or to the standby position. In this case, the permutation movement of the membrane can occur due to the intrinsic elasticity of the membrane and / or using a spring element (for example, a coil spring). In addition, the membrane can also serve as a seal. For example, the membrane can be connected using a membrane holder with a rod, respectively, a compensating element.

The locking mechanism may include a locking element, which is preferably made elastic, in order to change its original shape under the action of force, due to which, for example, unlocking, closing position and / or strengthening of the closing force can be achieved, and with the aim, in the absence of force, returning to its original form, whereby, for example, blocking, waiting position, opening position and / or deactivation of the closing force gain can be achieved.

The locking element preferably has a base, which is located on the piston rod, and at least one, preferably several locking levers that protrude from the base. In addition, the locking element may preferably have at least one locking portion for creating a locking. A stop is preferably formed between the locking portion and the fitting portion, respectively the supporting portion (preferably the fitting portion, the supporting portion, respectively the locking portion of the fitting portion near, respectively, on the circumferential edge of the central hole).

In addition, the locking element may contain at least one switching section to ensure the release, respectively, blocking the locking of the locking section. The locking portion and / or the switching portion are preferably located in the free end region of the at least one locking element.

In addition, the locking mechanism may include a switching element (for example, a tapered switching surface) for releasing and / or blocking the locking of the locking portion. The switching element is preferably connected to the rod, respectively, the compensating element, and / or can move together with the rod, respectively, the compensating element. Preferably, the switching element is provided on the membrane holder, which is located on the rod, respectively, the compensating element, however, can also be provided on the rod, respectively, the compensating element.

In one exemplary embodiment, the switching element and / or the locking body are provided for movement, for example, from the standby position and / or the opening position in the axial direction in the direction of the locking element (respectively, the piston), in particular, for the load using the fluid located on the inlet side medium and / or using a closing force amplifier, in order to achieve a closing position and / or increasing the closing force and / or unlocking the locking of the locking portion, respectively the deformation of the locking element from of the original form, preferably radially inwardly.

In addition, the switching element and / or the locking body are preferably provided for moving from the standby position and / or the closing position in the axial direction from the locking element (respectively, the piston), in particular for loading by the external medium (for example, by means of air, compressed air) through the second control input, in order to achieve the standby position and / or the opening position and / or to block the locking of the locking portion, respectively, to ensure the return of the locking of the element is preferably radially outward in its original form.

In one embodiment, the locking body may preferably be provided at the free end of the rod, respectively, of the compensating element.

The fluid valve may comprise a valve seat that has at least one conical section and preferably at least one cylindrical section.

In addition, the valve for the fluid may contain a locking body, which has at least one conical section and preferably at least one cylindrical section.

In addition, it is possible that the locking body is sealed with a sealing means (for example, a sealing ring, preferably a ring with a circular cross section, and / or a sealing lip), respectively provided with sealing means. Preferably, the conical portion of the locking body has a circumferential sealing lip or o-ring, in particular provided to fit in the closing position with the seal against the conical portion of the valve seat.

The cylindrical portion of the locking body is preferably provided for forming, in particular in the standby position, but it is also possible in the opening and / or closing position together with the cylindrical portion of the valve seat, in particular in the axial direction of the annular gap, which along the entire axial length has essentially a constant value, respectively, the width of the slit, and / or passes coaxially and parallel to the piston rod, the rod and / or the compensating element. Preferably, the diameter of the cylindrical portion of the locking body is greater than the diameter of the rod, respectively of the compensating element, and / or less than the diameter of the cylindrical portion of the valve seat, with the aim of forming an annular gap.

In one embodiment, the cylindrical portion of the locking body is located at the free end of the locking body, while the conical portion of the locking body may be located, for example, between a bar, respectively, a compensating element, and a cylindrical portion.

In another exemplary embodiment, the locking body comprises a first conical section, a second conical section and a cylindrical section, wherein the cylindrical section can be located between the first conical section and the second conical section, while the first conical section can be located, for example, between the bar, respectively, a compensating element, and a cylindrical section, and the second conical section at the free end of the locking body.

The locking part, the fitting part and / or the membrane holder can be made of metal, preferably resistant to corrosion, in particular hardened steel.

In addition, it should be mentioned that the invention is not limited to the above fluid valve as a separate component. The invention also encompasses the entire varnish installation with a check valve according to the invention, with the aim of guiding paint residues arising when changing the paint of the varnish installation through the return pipe to the return, where they are economically disposed of.

Within the scope of the invention, it is also possible to integrate the discharge stop function with the aid of a proprietary medium according to the invention into the main needle valve of the atomizer. In this case, it is possible to pump through the main needle in the nozzles without returning.

In addition, the invention also contains a method of changing the ink with at least one of the following steps, respectively, with one of the working phases:

a) varnishing with the supply of varnish through the pipeline for paint;

b) flushing the paint line through a check valve to a check line;

c) washing the lacquering component and the channel of the main needle (main needle, nozzle, air damper or bell-shaped plate);

d) putting the discharge stop valve in the standby position; this working phase may overlap in time with the working phase c);

f) filling (under pressure) the pipeline for the paint to the check valve (discharge stop valve), while the check valve automatically closes when there is paint at its inlet;

f) internal effects of the transmission characteristics (in particular of the fluid through the valve, for example, depending on the inlet side of the fluid).

Finally, the invention contains a new application of such a check valve in a coating system.

Other preferred modifications of the invention are characterized in the dependent claims or are explained in detail below together with a description of preferred embodiments with reference to the accompanying drawings, in which is schematically depicted:

figure 1 - the check valve according to the invention, which at the end of the discharge process switches using its own medium in the closing position;

figure 2 - modification of the check valve according to figure 1, in which the control air for closing using the external environment of the check valve is supplied through the valve needle;

figure 3 - modification of the check valve according to figure 1 with a pneumatic closing force amplifier, while the closing force amplifier has a slide valve;

figure 4 - modification of the check valve according to figure 3 with another embodiment of the amplifier closing force;

5 is a modification of the check valve according to figure 1 with only one single connection for external control air, which serves to open with the help of the external environment of the check valve;

6 is an alternative embodiment of a check valve according to the invention with a membrane;

7 is a modification of the check valve according to figure 1 with an additional piston for opening with the help of an external pneumatic medium of the check valve;

Fig.8 is a modification of the check valve according to Fig.7, while it is possible to close the check valve using an external pneumatic medium;

Fig.9 is a modification of the check valve according to Fig.8, while the piston is connected through a gap-compensating element with a locking body;

figure 10 - modification of the check valve according to figure 9 with a pre-control valve for closing with the help of the external environment of the check valve;

11 is a modification of the check valve according to Fig.7, while the locking body has a perforated disk;

figa-12D - various operating conditions of the check valve according to the invention;

Fig is a diagram of a conventional coating installation with a return pipe;

figa - check valve, similar to the check valve according to Fig.9, while the check valve is shown in the discharge state, on an enlarged scale;

figv - check valve according figa in the closing position, in which the check valve can be translated using applied on the inlet side of the paint pressure and / or using compressed air;

figs - check valve according figa and 14B in the open flushing position for flushing the pipeline for paint;

Fig. 15 is an alternative embodiment of a check valve according to the invention with an increase in closing force in the discharge / standby position (without actuation by paint);

Fig.16 - locking element of the locking mechanism of the check valve according to Fig.15;

FIG. 17A is a check valve according to FIG. 15 in the closing / lacquering position (with actuation with paint and an increase in closing force);

figv - check valve according to Fig in the flushing position (with support for compressed air);

figa-18C - various embodiments of valve seats, rods, respectively compensating elements, and locking bodies, in accordance with examples of the invention;

Fig - installation position of the valve for the fluid according to the invention.

The exemplary embodiment of FIG. 1 partially coincides with the usual exemplary embodiment of FIG. 13 indicated at the beginning, so that to avoid repetition, a reference is made to the above description, with the corresponding individual parts being denoted by the same position.

In this case, the check valve 8 has a cylinder 12 in which the piston 13 is located with the possibility of shear, while the piston 13 is sealed relative to the inner wall of the cylinder 12 by means of a seal 14, which makes it possible to control the piston using compressed air. To do this, the check valve 8 has two connections 15, 16 for compressed air, while the connection 15 for compressed air enters the cylinder 12 under the piston 13 and allows the check valve 8 to be closed using the external environment, while the connection 16 for compressed air enters the cylinder 12 above the piston 13 and provides the possibility of pneumatically performed from the outside opening of the check valve 8.

In addition, the check valve 8 has two coil springs 17, 18, while the upper coil spring 17 is weaker than the lower coil spring 18.

The upper coil spring 18 rests with its upper side on the inner end surface of the cylinder 12 and presses the piston 13 from the top in the axial direction.

In contrast, the lower spring 17 rests with its lower side on the thrust plate 26 and presses axially from below on the piston 13, while the thrust plate 26 has in the middle a central hole for passage of the piston rod 20.

The piston rod 20 has a flange 27 on its lateral surface that abuts against the thrust plate 26 from below and carries the thrust plate 26 upward when the piston rod 20 moves from the shown standby position to the closing position.

In contrast, in the standby position shown in the figure, the thrust plate 26 is supported by its lower side on the annular support 28.

In addition, the check valve 8 has a locking body 19, which is connected through the valve needle 20 to the piston 13, so that the movement of the piston 13 is transmitted to the locking body 19. At the same time, the locking body 19 sits in the valve seat 21, while in the position shown in the figure opening the return valve 8 between the locking body 19 and the valve seat 21 there is a narrow annular gap.

In this case, the annular gap between the locking body 19 and the valve seat 21 is of such a size that the air or foam entering the inlet side is passed essentially unobstructed, and there is no pressure difference between the inlet side and the outlet side of the locking body 19.

If on the inlet side of the check valve 8 there is a more viscous paint, the varnish flow through the annular gap between the locking body 19 and the valve seat 21 is hindered, due to which there is a pressure difference between the inlet side and the output side of the locking body 19. This pressure difference between the inlet side and the output side of the locking body 19, in turn, creates a closing force on the locking body 19, so that the locking body 19 moves from the standby position, respectively opening, shown in the figure, up to the polo ix closing and back check valve 8 is closed.

In addition, the check valve 8 can also be translated by external control to the closing position by supplying compressed air to the control air connection 15.

In addition, the check valve 8 can be opened again by supplying compressed air to the upper compressed air connection 16.

The exemplary embodiment shown in FIG. 2 basically coincides with the exemplary embodiment shown in FIG. 1, the description of which is given above, so that a reference to it is made to exclude repetitions, while the corresponding individual parts are denoted by the same positions.

A feature of this exemplary embodiment is that the control air connection 15 for closing the check valve 8 extends coaxially through the valve needle 20.

The exemplary embodiment shown in FIG. 3 again basically coincides with the exemplary embodiment shown in FIG. 1, the description of which is given above, so that a reference to it is made to exclude repetitions, while the corresponding individual parts are denoted by the same positions.

A feature of this exemplary embodiment is that the check valve 8 in this exemplary embodiment has a closing force amplifier that enhances the closing force with its own medium. For this, the closing force amplifier has an amplification valve, which selectively opens or closes the connection 15 for compressed air. The amplification valve consists essentially of a valve gate 22, which is mounted externally on the underside of the piston 13 and protrudes downward through the inlet of the compressed air connection 15.

In the open position of the check valve 8 shown in the figure, the valve shutter 22 closes the inlet of the compressed air connection 15, so that the compressed air in the compressed air connection 15 does not act on the piston 13.

In contrast, when the locking body 19, on the basis of actuation using its own medium, moves slightly from the opening position shown in the figure in the direction of the closing position, the valve shutter 22 releases the air inlet of the connection 15 for compressed air, after which the connection 15 compressed air acts on the lower side of the piston 13 and pushes it further up in the direction of the closing position.

The exemplary embodiment shown in FIG. 4 partially coincides with the exemplary embodiment shown in FIG. 3, the description of which is given above, so that a reference to it is made to exclude repetitions, while the corresponding individual parts are denoted by the same positions.

A feature of this exemplary embodiment is the structural embodiment of the closing force amplifier. Thus, the compressed air connection 15 enters axially below into the cylinder 12, while the compressed air connection 15 inlet in the opening position shown in FIG. 4 is indirectly closed by the piston 13, so that a relatively small force acts on the piston 13, since the input the connection port 15 for compressed air has only a relatively small cross section.

When the piston 13 releases the inlet of the compressed air connection 15 when the closing movement of the check valve 18 begins, then immediately the entire lower side of the piston 13 is loaded with the pressure supplied through the compressed air connection 15, due to which a significantly greater closing force arises. In this case, the gear ratio of the force is determined by the ratio of the cross section of the inlet of the connection 15 for compressed air, on the one hand, and the piston 13, on the other hand.

The exemplary embodiment shown in FIG. 5 basically coincides with the exemplary embodiment shown in FIG. 1, the description of which is given above, so that a reference to it is made to exclude repetitions, while the corresponding individual parts are denoted by the same positions.

A feature of this exemplary embodiment is that there is no connection 15 for compressed air provided in FIG. Thus, the exemplary embodiment shown in FIG. 5 does not allow externally closing the check valve 8, so that the closing movement is carried out exclusively by means of its own medium.

Fig. 6 shows a fundamentally different example of a check valve according to the invention, which, however, also partially coincides with the exemplary embodiment shown in Fig. 1, the description of which is given above, so that to avoid duplicates, reference is made to it, while the corresponding individual parts denoted by the same position.

A feature of this exemplary embodiment is that an elastic membrane 23 is located in the cylinder 12, while the locking body 19 is connected to the middle of the membrane 23, so that the membrane 23, depending on its deflection, creates a corresponding return force.

In addition, the cylinder 12 has on its upper side a compensating hole 24 to ensure equalization of pressure during movement of the membrane 23.

The exemplary embodiment shown in FIG. 7 is a combination of the exemplary embodiment of FIG. 6 with the previous exemplary embodiments, so that to avoid duplicates, reference is made to the above description, with the corresponding individual parts being denoted by the same position.

A feature of this exemplary embodiment is that in addition to the membrane 23, the piston 13 is also located in the cylinder 12, while the valve needle 20 connects the locking body 19 with the membrane 23 and the piston 13. Moreover, the locking body 19 can be moved due to the above-mentioned action pressure to the opening position by supplying the corresponding pressure to the compressed air connection 16.

The exemplary embodiment shown in FIG. 8 basically coincides with the exemplary embodiment shown in FIG. 7, so that to avoid repetitions, reference is made to the above description, with the corresponding individual parts being denoted by the same reference numbers.

A feature of this exemplary embodiment is that in addition to connecting 16 for compressed air to open the check valve 8, a connection 15 for compressed air for closing the check valve 8 is also provided.

The exemplary embodiment shown in FIG. 9 generally coincides with the exemplary embodiment shown in FIG. 8, so that to avoid repetitions, reference is made to the above description, with the corresponding individual parts being denoted by the same reference numbers.

A feature of this exemplary embodiment is that the piston 13 is connected to the membrane 23 and the locking body 19 not rigidly, but through a mechanical compensating element that allows mechanical clearance. This means that during the closing movement of the locking body 19, only the membrane 23 moves, while the gap of the compensating element between the piston 13 and the membrane 23 also prevents the movement of the piston 13. Thus, the gap of the compensating element is slightly larger than the movement of the locking body 19 between the opening position and closing position.

The exemplary embodiment shown in FIG. 10 basically coincides with the exemplary embodiment shown in FIG. 9, so that to avoid repetitions, reference is made to the above description, with the corresponding individual parts being denoted by the same position.

A feature of this exemplary embodiment is that the lower side of the piston 13 can be loaded with compressed air through the preliminary control valve 25 in order to support the closing movement of the check valve 8. The control valve 25 of the preliminary control is controlled depending on the pressure in the paint conduit 5. Therefore, the pre-control valve 25 has a control input that is connected to the paint line 5.

When the pressure in the paint line 5 at the end of the injection process rises because fresh paint is in the paint line 5, the increasing pressure in the paint line 5 causes the pre-control valve 25 to be actuated, thereby lowering the piston 13 is pressurized. Due to this, the closing force is enhanced with the help of its own medium, which leads to the quick closing of the check valve.

The exemplary embodiment of the check valve 8 according to the invention shown in FIG. 11 basically coincides with the aforementioned exemplary embodiments, so that to avoid repetition, reference is made to the above description, with the corresponding individual parts being denoted by the same position.

Moreover, the feature is that the locking body 19 has a perforated disk, while the fluid must pass through the holes in the perforated disk.

On figa-12D shows the various working stages of the check valve according to the invention when changing paint.

Thus, FIG. 12A first shows the position of the check valve 8 when flushing the paint line 5. To this end, the locking body 19 is squeezed out of the valve seat by means of a pneumatic medium in order to open the check valve 8. The residues of the flushing agent, paint foam, compressed air and residual paint that arise during washing are then sent through the return pipe 7 to the return.

In contrast, FIG. 12B shows the status of the check valve 8 when new ink is injected. In this case, the check valve 8 is not actuated by the pneumatic medium, so that the spherical locking body 19 does not fit loosely in the valve seat and allows only air or foam to pass through.

In contrast, FIG. 12C shows the state of the check valve 8 at the end of the injection process when the paint line 5 is already filled with fresh varnish, which has a relatively high viscosity. The relatively high viscosity of the flowing varnish leads to the fact that the check valve 8 is closed by its own medium due to the fact that the spherical locking body 19 is pressed against the valve seat.

Finally, FIG. 12D shows the state of the check valve during subsequent varnish application after completion of the previous injection process. In this state, the spherical locking body 19 is drawn into the valve seat by means of an external pneumatic medium in order to reliably close the check valve.

The check valve 8 shown in FIGS. 14A-14C is basically the same as the check valve shown in FIG. 9, so that reference is made to the above description to avoid duplicates, with the corresponding individual parts being denoted by the same reference numbers.

As shown on an enlarged scale in FIGS. 14A-14C, the piston rod 20 is hollow and has a central bore. In this central hole in the piston rod 20, a rod 29 is mounted with the possibility of axial displacement, while the rod 29 is rigidly connected to the locking body 19 and clamped in the middle hole in the membrane 23.

In addition, in the Central hole of the piston rod 20 there is a coil spring 30, which rests on its upper side on the piston 13, and on its lower side on the upper end surface of the rod 29. Thus, the spiral spring 30 and the membrane push the piston 13 and the rod 29 and thereby also the locking body 19 from each other in the axial direction. However, the return function can also be performed only by a membrane without a coil spring 30.

In addition, it should be noted that at the lower end of the piston rod 20, an annular circumferential shoulder-shaped abutment 31 is formed to restrict the upward movement of the piston 13 (not the movement of the piston 13 but the “package” between the piston 13 and the thrust plate 32 is limited). For this, the check valve 8 has a thrust plate 32, while the thrust plate 32 has in the middle a hole through which the piston rod 20 passes.

In the discharge position according to FIG. 14A and in the closing position according to FIG. 14B, the stop 31 abuts with its upper side against the circumferential edge of the middle hole in the stop plate 32, so that the piston 13 cannot move up.

In contrast, in the flushing position of FIG. 14C, the piston 13 with the piston rod 20 is moved downward so that the stop 31 does not abut against the thrust plate 32. The stop 31 abuts against the bottom of the valve in order to limit the downward movement of the valve. In this position, the thrust plate 32 should abut against the bottom of the valve.

In addition, FIGS. 14A-14C show on an enlarged scale that there is an elongated hole in the rod 29 that includes a gripping pin 33 that is connected to the piston rod 20. The geometry of the gripping pin 33 and the elongated hole are so coordinated with each other so that the elongated hole in the rod 29 provides a mechanical clearance for the gripping pin 33, so that the piston rod 20 and the piston 13, on the one hand, and the rod 29 and the locking body 19, on the other hand, have an axial clearance.

Below is a description of the discharge position of the check valve 8 shown in FIG. 14A. The discharge position of the check valve 8 is set when the paint is changed, when the paint line 5 is washed and a new ink is pumped into the paint line 5 up to the main needle valve 6.

In this discharge position, neither the compressed air connection 15 nor the compressed air connection 16 has control air to drive the piston 13. In this case, the position of the check valve 8 is determined only by the interaction of the elastic membrane 23 and the coil springs 17, 18 and 30. Thus, the membrane 23 installs the rod 29 and thereby also the locking body 19 in the neutral position shown in the figure, in which an annular gap is located between the locking body 19 and the valve seat 21, which allows be output through the first return line fed through conduit 5 air paint.

The spiral spring 17 pushes the piston 13 and thereby also the piston rod 20 up, until the stop 31 will not abut against the thrust plate 32.

Finally, the coil spring 30 pushes the rod 29 axially downward relative to the piston 13.

Below is a description of the closing position of the check valve 8 shown in FIG. 14B, wherein the check valve 8 can optionally be brought into the closing position by means of a paint pressure applied on the inlet side or by compressed air.

The following is a first description of how the check valve 8, when injected, is translated based on the ink pressure applied on the inlet side from the discharge position shown in FIG. 14A to the closing position shown in FIG.

If, when a new ink is injected through the paint line 5, no more air or ink foam is supplied, but only fresh ink, then the higher viscosity of the fresh ink leads to a higher pressure on the locking body 19, which thereby presses up against the elastic return force of the membrane 23. In this case, the mechanical clearance between the piston rod 20 and the rod 29 allows the piston 13 to remain in the same position as in the discharge position shown in FIG.

Finally, FIG. 14C shows the flushing position of the check valve 8, in which the check valve 8, regardless of the ink pressure applied to the inlet side, is open to allow washing of the paint conduit 5 through the return conduit 7.

For this, the piston 13 is loaded with compressed air through the connection 16 for compressed air. The movement of the piston 13 exceeds the mechanical clearance between the elongated hole in the rod 29 and the gripping pin 33 in the piston rod 20. This leads to the fact that the piston 13 with the piston rod 20 pushes the rod 29 and thereby also the locking body 19 down. Due to this, the locking body 19 is squeezed out of the valve seat 21, thereby opening the check valve 8.

On Fig again shows another example of a check valve according to the invention, which, however, also partially coincides with the above examples, so that to avoid repetition, reference is made to the above description, with the corresponding individual parts are denoted by the same position.

A feature of this exemplary embodiment is, inter alia, that it enhances the closing force by means of a locking mechanism. In particular, the closing force amplifier is activated using its own medium depending on the inlet side of the fluid in order to achieve an increase in closing force, preferably by releasing the locking mechanism with its own medium depending on the inlet side of the fluid in order to achieve the force gain closing and / or moving the fluid valve to the closing position.

For this, FIG. 15 shows, in particular, that a locking element 34 is arranged on the piston rod 20. The locking element 34 comprises a cylindrical base 35a that is coaxially mounted on the piston rod 20, and preferably four locking levers 35b that protrude from the base 35a ( see Fig. 16). Each of the locking levers 35b has a switching section, preferably a beveled switching surface 36, and a locking section, preferably a locking surface 37. The locking sections 37 are provided for forming a blocking and releasing locking with an adjacent, abutting, respectively supporting part 40.

The switching sections 36 are provided for interacting with the switching element 39, whereby the release and / or blocking of the locking between the locking sections 37 and the adjacent part 40 can be achieved. Thus, the switching element 39 is provided for interacting with the switching sections 36 for releasing and / or blocking the locking between the locking sections 37 and the adjacent portion 40, in particular for engaging and disengaging. The switching element 39 is connected to the compensating element, respectively, with the rod 29. In particular, the switching element 39 is provided on the membrane holder 38, which is located on the compensating element, respectively, of the rod 29. The switching element 39 preferably comprises a circumferential bevelled switching surface, which is located coaxially to the compensating element , respectively, the rod 29, and is provided for interaction with respectively beveled switching surfaces to switch parts 36. The switching element 39 is provided for movement together with the rod 29, respectively, the compensating element, and / or the locking body 19.

In particular, the locking element 34 is preferably made elastic using the protruding levers 35b to form, with the adjacent part 40, a switchable (lockable / unlockable) snap, lock and / or clamp connection.

As further shown in FIG. 15, the adjoining portion 40 has a central opening in the middle for passing the locking element 34 (in particular, the locking levers 35b and / or the locking sections 37), the piston rod 20 and / or the rod 29, respectively, of the compensating element. In addition, the adjacent portion 40 is fixed to the inner side of the wall of the cylinder 12, respectively, to the wall of the check valve body 8. The adjacent portion 40 is preferably provided so that the coil spring 17 has its lower side (in particular, on the piston side, i.e., in FIG. .15 in the axial direction at the top) could lean on the adjacent part 40 and press axially from the bottom up on the piston 13, and / or to provide on the peripheral edge, respectively, near the central hole (on the side of the locking body, i.e., in FIG. 15 in axial direction at the bottom) of the adjacent, supporting, respectively, locking portion for the locking portions 37. The adjacent portion 40 may preferably be structurally and / or functionally similar or even substantially identical to the thrust plate 32. The adjacent portion 40 is preferably positioned between the membrane 23 and the spiral spring 17 and / or piston 13.

In general, the closing force amplifier and / or locking mechanism according to FIG. 15 operate as follows:

When injecting paint, the valve 8 is without pneumatic pressure in the discharge position, respectively, waiting. In this case, the locking body 19 forms a narrow annular gap 50 relative to the valve seat 21. The incoming paint squeezes air and aerosol from the air and flushing means from the paint channels (from the paint switch up to the spray gun) through the valve discharge (stopping) port 50 of the valve into the return pipe 7. Upon arrival of the paint, the locking body 19 closes due to more viscous paint (without control sensors and preferably instantly). For reliable operation when applying varnish when the paint comes to the locking body 19, the locking mechanism is released, due to which, by means of springs, an increase in the closing force is achieved, preferably by means of a spiral spring 17, which is located between the adjacent part 40 and the piston 13.

During subsequent injection, the compensating element, respectively, the rod 29, is shifted by the incoming paint upward in Fig. 15. In this case, the switching element 39, preferably located on the membrane holder 38, shifts the locking levers 35b radially inward above the switching section 36. When the locking levers 35b, respectively, the locking sections 37 are disengaged from the adjoining portion 40, the coil spring 17 is unloaded, and thereby the locking spring the body 19 is tightly pressed against the valve seat 21.

16 shows an enlarged scale of the locking element 35. The locking element 35 comprises a cylindrical base 35a and four locking levers 35b protruding from it. Each of the locking levers 35b has a switching portion 36 and a locking portion 37.

On Fig shows a section of the check valve in the discharge / standby position (without actuating with paint). The piston 13 is pushed by a spiral spring 17 up. However, its movement is limited by the locking levers 35b, which by means of the locking sections 37 are engaged (locked) with the adjacent part 40. Thus, the locking sections 37 together with the adjacent part 40 form a stop, in particular with the circumferential edge of the central hole in the adjacent part 40 .

The locking pin 33 is positioned at the upper end of the elongated hole with a membrane, respectively, additionally with a coil spring 17. The locking body 19 is positioned so that between the valve seat 21 and the locking body 19 is formed an injection, respectively annular slot 50.

On figa shows a section of the check valve of Fig.15 in the closing position (actuated by paint), respectively, the position of the application of varnish with the strengthening of the closing force. The switching element 39 on the membrane holder 38 is first moved upward with the ink supplied through the ink duct 5. Due to this, the switching element 39 is engaged with the switching sections 36 of the locking levers 35b so that the locking levers 35b are pressed radially inward (PR), whereby the locking between the locking levers 35b, in particular the locking sections 37, and the adjacent part 40 is released, opens accordingly. Thus, the piston 13 can be pushed by a spiral spring 17 up. Thus, the locking body 19 is first loaded upward with the ink supplied through the paint conduit 5, and then heavily loaded upward with the closing force amplifier, which, with the help of the coil spring 17, creates an increased closing force in order to provide a preferably tight and reliable seal . The grip pin 33 is positioned using paint pressure at the lower end of the elongated hole.

In particular, when comparing Figs. 15 and 17A, it can be seen that the switching element 39 is provided for moving from the standby / discharge position (see Fig. 15) in the axial direction of the RA in the direction of the locking element 34 to reach the closing position (see. 17A) and / or to increase the closing force and / or to release the stopper of the stop sections 37 with the adjacent part 40, in particular by deforming the stop element 34 from its original shape (see FIG. 16) radially inward.

On figv shows a section of the check valve of Fig.15 in the flushing position with the support of compressed air. The gripping pin 33 is located at the upper end of the elongated hole. The piston 13 is pressed down using compressed air supplied through the connection 16 for compressed air. In addition, the coil spring 17 is compressed. In addition, the locking body 19 moves downward, due to which a flushing gap 51 is formed between the locking body 19 and the valve seat 21. In the flushing position, the stop sections 37 do not form a stop with the adjacent part 40, t. e. are not engaged with the adjacent part 40. In particular, the locking portions 37 are located at a distance from the adjacent part 40, respectively, shifted beyond the locking position.

In particular, it follows from the comparison of FIGS. 15, 17A and 17B that the switching element 39 is provided for moving from the closing position (see FIG. 17A) and / or the standby / discharge position (see FIG. 15) in the axial direction in the direction from the locking element 34 to achieve the standby / discharge position (see FIG. 15) and / or the opening position (see FIG. 17B), and / or to form or block, respectively, the locking of the locking sections 37 with the adjacent part 40, in particular by returning the locking element 34 to its original shape (see Fig. 16).

On figa-18C shows in detail various embodiments of valve seats, rods, respectively compensating elements, and locking bodies according to examples of the invention, which partially coincide with the above examples and can be provided in the above valves, so that to prevent repetitions reference is made to the above description, with the corresponding individual parts indicated by the same positions.

On figa schematically shows on an enlarged scale an embodiment according to the principle of axial clearance, in particular a modified rod 29 (respectively, a compensating element) and / or a modified locking body 19 in the area of the valve seat 21. The locking body 19 is made conical, preferably with an extension to pipeline 5 for paint. In addition, the valve seat 21 has a conical section, preferably expanding to the pipe 5 for paint. The locking body 19 is at least in separate sections located in a conical section of the valve seat 21. The locking body 19 comprises a circumferential sealing lip 19x. The sealing lip 19x is adjacent with the seal in the closing position to the conical portion of the valve seat 21, while in the flushing position and / or the standby / discharge position between the sealing edge 19x and the conical portion of the valve seat 21, an injection gap 50 or an annular gap is formed. The sealing lip 19x shown in FIG. 18A is located on the free end of the locking body 19.

Fig. 18A shows on an enlarged scale an embodiment according to the principle of a radial gap, in particular another modified rod 29 (respectively, a compensating element) and / or another modified locking body 19 in the area of the valve seat 21. The locking body 19 contains a first conical section 19a, a second conical section 19b and a cylindrical section 19c, which is located between the first and second conical sections 19a, 19b. The first conical section 19a extends from the rod 29, respectively of the compensating element, to the cylindrical section 19c, while the second conical section 19b is located on the free end of the locking body 19. The first and second conical sections 19a, 19b preferably expand each in the direction of the paint pipe 5. The valve seat 21 comprises a cylindrical section and a conical section, which preferably expands to the paint line 5. The conical portion of the valve seat 21 is located at the free end of the valve seat 21, with the cylindrical portion of the valve seat 21 located in FIG. 18B coaxially directly above the conical portion of the valve seat 21. The diameter of the cylindrical portion 19c of the locking body 19 is larger than the diameter of the rod 29, respectively, of the compensating element. A cylindrical section 19c of the locking body 19 is provided for forming, with a cylindrical section of the valve seat 21, an axially extending annular gap 60, which has a substantially constant axial length “a”. Preferably, the axial slot 60 extending in the axial direction extends coaxially and parallel to the piston rod 20, the rod 29, respectively, the compensating element. The sealing lip 19x shown in FIG. 18B is located on the free end of the locking body 19.

On figs schematically shown on an enlarged scale an embodiment according to the principle of a radial gap, in particular again another modified rod 29 (respectively, a compensating element) and / or again another modified locking body 19 in the area of the modified valve seat 21. The locking body 19 contains a conical section 19a and the cylindrical section 19c. The conical section 19a is located between the rod 29, respectively, the compensating element, and the cylindrical section 19c, while the cylindrical section 19c of the locking body 19 is located on the free end of the locking body 19. The conical section 19a is preferably expanded in the direction of the pipe 5 for paint. The diameter of the cylindrical section 19c of the locking body 19 is larger than the diameter of the rod 29, respectively, of the compensating element. In addition, the valve seat 21 includes a cylindrical section and a conical section, which preferably expands to the pipe 5 for paint. The cylindrical portion of the valve seat 21 is located on the free end of the valve seat 21, with the conical portion of the valve seat 21 located in FIG. 18C coaxially directly above the cylindrical portion of the valve seat 21. The locking body 19 comprises a circumferential sealing lip 19x. The sealing lip 19x is adjacent to the seal in the closing position to the tapered portion of the valve seat 21.

A cylindrical section 19c of the locking body 19 is provided for forming, with a cylindrical section of the valve seat 21, an axially extending annular gap 60, which along its axial length "a" has a substantially constant value, respectively, a constant width of the gap. Preferably, the axially extending annular gap 60 extends coaxially and parallel to the piston rod 20 and / or the rod 29, respectively, of the compensating element. The sealing lip 19x shown in FIG. 18C is located in the axial direction after the free end of the locking body 19.

Compared to the embodiment shown in FIG. 18A, the embodiments shown in FIGS. 18B and 18C are more preferred since they provide better paint pressure ratios. In the embodiment shown in FIG. 18A, it is possible that a part of the pressure of the paint is also created behind the locking body, and due to this, the force for closing during injection is reduced.

In the embodiment according to FIG. 18B and, in particular, the embodiment according to FIG. 18C, due to the longer path of the rod during the closing process with a constant gap, they can better compensate for the length tolerances of the valve structural elements during this closing stroke (advantage: long stroke of the rod, respectively, of the compensating element, more simple keeping of manufacturing tolerances). Due to the longer closing stroke, it is also possible to reliably and improve closing in embodiments with a closing force amplifier.

A fluid valve for reducing paint loss, in particular for reducing paint loss during injection after a paint change, can preferably be used in various positions. As shown in FIG. 19, for example, in the paint switch FW (see position RF2), in the metering pump DP (for example, instead of the position of the bypass valve BV), in the spray gun Z (see position RF1), special paint supply systems and other applications, etc. In addition, a valve for the fluid, respectively, a valve for stopping paint, can be used in the milking area. A valve for a fluid, respectively a valve for stopping paint, can be used (in particular, always) to remove air from the channels for the paint, respectively, a coating agent when injecting paint, and self-closing when the paint comes in, in order to reduce or at best prevent losses paints. In addition, many other applications are possible.

The invention is not limited to the above examples. Many variations and modifications are possible, in which the idea of the invention is also used and which are therefore included in the scope of protection. In particular, the invention also claims to protect the subject matter of the dependent claims regardless of the subject matter of the preceding claims.

List of items

1 Coating system

2 Rotary atomizer

3 bell-shaped plate

4 Spray Jet

5 Paint line

6 Main needle valve

7 Return pipe

8 Check valve

9 light source

10 Sensor

11 control unit

12 cylinder

13 piston

14 Seal

15 Connection for compressed air

16 Connection for compressed air

17 spiral spring

18 spiral spring

19 Locking body

20 Valve needle, respectively piston rod

21 valve seat

22 valve

23 Membrane

24 Compensating hole

25 Pre-control valve

26 thrust plate

27 Capture

28 Prop

29 Bar

30 spiral spring

31 Emphasis

32 thrust plate

33 Grip pin

34 locking element

35a Base

35b Lock Lever

36 switching section

37 Locking area

38 Membrane holder

39 Switch element

40 Part of the fit, support, respectively emphasis

50, 60 Annular / discharge slot (standby / discharge position)

51 annular gap (opening / flushing position)

19a, 19b Conical section of the locking body

19c Cylindrical section of the locking body

19x Circumferential sealing lip of the locking body

FW paint switch

DP dosing pump

BV Bypass Valve

RF Return

HV Main Needle Valve

Z Sprayer

Claims (28)

1. A valve (8) for the fluid, in particular a check valve (8), for returning the remainder of the paint, flushing agent, air and / or compressed air from the pipe (5) for the paint when changing the paint in the coating unit (1), in particularly when injecting new paint when changing paint, having
a) an opening position in which the valve (8) for the fluid is at least partially open, in particular for flushing the pipe (5) for paint with flushing means and for injecting new paint into the pipe (5) when changing the paint, and
b) a closing position in which the valve (8) for the fluid is closed, in particular for applying a new varnish after changing the paint,
c) wherein the valve (8) for the fluid is arranged to swap between the opening position and the closing position,
d) wherein the fluid valve (8), depending on the fluid on the inlet side, switches by means of its own medium to the closing position and / or influences the transmission characteristics,
characterized in that
e) the process of switching the valve (8) for the fluid is controlled by the density of the mass located on the inlet side of the fluid. 2. The valve (8) for the fluid according to claim 1, characterized in that
a) the valve (8) for the fluid is a check valve (8), in order to direct the residual paint, flushing agent, air and / or compressed air from the paint line (5) to the return, when changing the paint,
b) the check valve (8), due to its design, distinguishes between paint, on the one hand, and compressed air and air-containing foam, on the other hand,
c) the check valve (8) independently and due to its design switches to the closing position when paint is located on the check side of the check valve (8), and / or
d) the check valve (8) independently and due to its design switches to the open position and / or remains in the open position when air and / or compressed air or paint foam is on the inlet side of the check valve (8). 3. The valve (8) for the fluid according to claim 1 or 2, characterized in that the valve (8) for the fluid switches between the opening position and the closing position depending on at least one of the following properties located on the inlet side of the fluid :
a) viscosity
b) state of aggregation
c) expansion under pressure,
d) electrical conductivity
e) optical properties (in particular, permeability to light and color),
f) thermal conductivity
g) vibration characteristics,
h) magnetic permeability
i) pressure. 4. The valve (8) for the fluid according to claim 1, characterized in that
a) the valve (8) for the fluid in the opening position is maximally open, in particular for flushing the pipe (5) for the paint with the maximum flow of flushing means,
b) the fluid valve (8) has, in addition to the opening position and the closing position, a standby position,
c) the valve (8) for the fluid in the standby position is at least partially open, in particular, to wait for new paint when injecting new paint, and
d) the fluid valve (8) automatically switches to the closing position only from the standby position, and not from the opening position. 5. The valve (8) for the fluid according to claim 1 or 4, characterized in that it also provides the possibility of external, in particular with the help of the external environment, control the check valve (8) using the valve actuator. 6. The valve (8) for the fluid according to claim 5, characterized in that it has
a) a first control input (15), in particular in the form of a first connection for control air, through which the valve (8) for the fluid can be switched to the closed position, actuated by the external medium, and / or
b) a second control input (16), in particular in the form of a second connection for control air, through which the valve (8) for the fluid can be switched to the open position, actuated by the external medium. 7. The valve (8) for the fluid according to claim 1, characterized in that it has
a) cylinder (12),
b) a piston (13) mounted with the possibility of shear in the cylinder,
c) a locking body (19) which is moved by a piston (13) between the opening position and the closing position,
d) a valve seat (21), wherein the locking body (19) closes the valve seat (21) in the closing position, while in the opening position, the locking body (19) opens the valve seat (21). 8. The valve (8) for the fluid according to claim 6 or 7, characterized in that
a) the first connection (15) for the control air enters on one side of the piston (13) in the cylinder (12) to switch the check valve (8) pneumatically to the closing position, and
b) the second control air connection (16) enters the cylinder (12) on the other side of the piston (13) to switch the check valve (8) pneumatically to the opening position and / or standby position. 9. The valve (8) for the fluid according to claim 1, characterized in that
a) the check valve (8) for switching to the closing position creates a closing force driven by its own medium, and
b) the closing force provided by the own medium can be enhanced by a closing force amplifier. 10. A valve (8) for a fluid according to claim 9, characterized in that
a) the closing force amplifier operates with actuation by means of an external medium, in particular pneumatically, or
b) the closing force amplifier operates by means of a spring and / or tension mechanism. 11. A valve (8) for a fluid according to claim 9 or 10, characterized in that it is possible to activate a closing force amplifier with its own medium, depending on the fluid on the inlet side in order to achieve an increase in closing force. 12. A valve (8) for a fluid according to claim 9, characterized in that
a) the closing force amplifier has an amplification valve,
b) the amplifier valve of the closing force amplifier selectively opens or closes the first connection (15) for the control air that enters the cylinder (12) and serves to close the valve (8) for the fluid,
c) the pressure applied to the first connection (15) of the control air increases the closing force when the amplification valve is open. 13. A valve (8) for a fluid according to claim 12, characterized in that
a) the amplification valve is a check valve and has a valve lock (22), which is connected to the piston (13),
b) the valve plug (22) closes the first control air connection when the piston (13) of the fluid valve (8) is in the open position,
c) the valve shutter (22) releases the first connection (15) for the control air when the piston (13) has moved a fraction of its stroke from the opening position in the direction of the closing position, so that a force amplification is applied. 14. A valve (8) for a fluid according to claim 12 or 13, characterized in that the first connection (15) for the control air radially extends to the side surface of the cylinder (12). 15. A valve (8) for a fluid according to claim 12, characterized in that
a) the first connection (15) for the control air axially goes to the end surface of the cylinder (12),
b) the first connection (15) for the control air is closed or opened directly or indirectly by the piston (13) of the valve (8) for the fluid,
c) the outlet of the first connection for the control air has a smaller cross section than the piston (13), while the ratio of the cross sections defines the force gain. 16. The valve (8) for the fluid according to claim 9, characterized in that
a) the closing force amplifier has a pressure-controlled preliminary control valve (25);
b) a pre-control valve (25) connects the first control air pipe to the first control air connection of the valve (8) for the fluid, so that the pressure in the first control air pipe supports the closing movement of the valve (8) when the valve (25) preliminary management open;
c) the pre-control valve (25) has a control inlet that is connected to a supply line (5) of the fluid valve (8), so that the pre-control valve (25) opens when in the supply line (5) of the valve (8) for fluid creates pressure. 17. The valve (8) for the fluid according to claim 1, characterized in that it is made in the form of a membrane valve with an elastic membrane (23), which carries a locking body (19). 18. The valve (8) for the fluid according to 17, characterized in that
a) the locking body (19) is connected to the piston (13),
b) the piston (13) is slidably mounted in the cylinder (12), and / or
c) on one side of the piston (13), the first connection (15) for compressed air enters the cylinder to pneumatically close the valve (8) for the fluid, and / or
a) on the other side of the piston (13), a second connection for compressed air enters the cylinder (12) to pneumatically open the valve (8) for the fluid. 19. A valve (8) for a fluid according to claim 17 or 18, characterized in that the piston (13) is loaded on one side or on both sides by the spring force of the spring (17, 18). 20. The valve (8) for the fluid according to claim 1, characterized in that the valve (8) for the fluid has a locking body (19) preferably with a perforated disk. 21. The valve (8) for the fluid according to claim 1 or 4, characterized in that the valve (8) for the fluid has a position sensor that detects whether the valve (8) for the fluid is in the closing position, especially the opening position or in the closing position or in the closing position or in the standby position. 22. The valve (8) for the fluid according to claim 7, characterized in that
a) the locking body (19) is connected through a compensating element with a piston (13),
b) the compensating element allows a clearance between the locking body (19) and the piston (13) and
c) the gap of the compensating element is greater than the movement of the locking body (19) from the opening position to the closing position, so that the locking body (19) without moving the piston can be moved from its opening position to the closing position using its own medium. 23. A valve (8) for a fluid according to claim 11, characterized in that the closing force amplifier comprises a locking mechanism, which is configured to switch its own medium depending on the fluid on the inlet side, and the locking mechanism comprises
a) the locking element (34), which
A1) at least in some areas made elastic;
a2) has a base (35a), which is mounted on the piston rod (20), and at least one locking lever (35b), which protrudes from the base (35a); and
a3) has at least one locking portion (37) for forming a locking portion of the locking portion (37) and at least one switching portion (36) for interacting with the switching element (39) in order to achieve release or blocking the locking of the locking portion (37) ; and
b) a switching element (39) for releasing or blocking the locking of the locking portion (37). 24. The valve (8) for the fluid according to item 23, wherein
a) the switching element (39) is provided for axial movement (RA) in the direction of the locking element (34) to achieve the closing position and / or to increase the closing force and / or to release the locking of the locking section (37), in particular by means of a radial deformation of the locking element (34) from its original shape; and / or
b) a switching element (39) is provided for axially moving away from the locking element (34) in order to reach the waiting position and / or the opening position and / or to block the locking of the locking section (37), in particular by returning the locking element (34) in its original form. 25. The valve (8) for the fluid according to claim 1, characterized in that
a) a valve seat (21) is provided which comprises a conical section and at least one cylindrical section; and
b) a locking body (19) is provided which comprises a first conical part (19a) and a second conical part (19b), the cylindrical portion (19c) of the locking body (19) being located between the first conical part (19a) and the second conical part (19b) ) locking body (19). 26. A valve (8) for a fluid according to claim 25, wherein
a) a cylindrical portion (19c) of the locking body (19) is provided for forming an annular gap (60) with a cylindrical portion of the valve seat (21), wherein the annular gap (60) has a substantially constant gap size in axial extent (a); and
b) the locking body (19) contains a circumferential sealing lip (19 ×), which is located on the free end of the locking body (19) or axially behind the free end of the locking body (19). 27. A varnishing installation (1), in particular for applying varnish to structural elements of a car body, comprising
a) a coating device (2) for applying a coating agent,
b) a pipe (5) for paint for supplying a coating agent to the application device (2),
c) the main needle valve (6), which is located in the pipe (5) for the paint upstream in front of the application device (2) and selectively opens or closes the coating means,
a) return pipe (7) for returning the residual coating agent, flushing agent, air and / or compressed air when changing the paint, while the return pipe branches upstream of the main needle valve (6) or downstream of the main needle valve from piping (5) for paint,
e) a check valve (8), which is located in the return pipe (7),
characterized in that
f) the check valve (8) is a fluid valve according to any one of claims 1 to 26, and / or
g) the main needle valve is a fluid valve according to any one of claims 1 to 26. 28. The use of a valve (8) for a fluid according to any one of claims 1 to 26 as
a) a check valve (8) in the paint system to return residual paint, flushing agent, paint foam, air and / or compressed air from the pipe (5) for paint when changing paint, or
b) the main needle valve in the spray gun.

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